Network, generic

U017C Lost Communication With Restraints System Sensor M

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

U017C is stored once restraint sensor M, the thirteenth remote crash sensor, falls silent. No manufacturer documents U017C publicly. For diagnosis it matters whether the code is current or only stored: according to the PSI5 working group, a brief drop in supply makes a sensor restart and send initialisation data first, so a loose contact can leave a history entry without a lasting fault. Wiggle tests on the connector and harness while watching live status are therefore more useful than replacing parts. Mechanical fit counts too: Audi, for example, inserts its capacitive door pressure sensors into the inner door panel with a seal and turns them to lock, and a poorly seated sensor after trim work can fail. U047D reports invalid data instead of silence. No MIL.

Likely causes

Intermittent contact at sensor M connector (history code)
Sensor not seated or sealed correctly after trim work
Sensor wiring chafed or open
Crash sensor M failed

Symptoms

  • Airbag warning lamp on or flickering
  • Code stored as history after the lamp went out again
  • Impact detection in the zone of sensor M unavailable while active

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€60–600
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

restraints sensor mcrash signal wiring

Related codes

U0151U017BU017DU047D

References: psi5.org, static.nhtsa.gov, bosch-mobility.com.